This application is based on Japanese Patent Application No. 11-318916 (1999) filed Nov. 9, 1999, the content of which is incorporated hereinto by reference.
1. Field of the Invention
The present invention relates to a card connector for electronic devices, such as cellular phones, telephones, PDAs (personal digital assistants), portable audio devices and digital cameras, and more specifically to a card connector with a reduced height which receives a two-stage thickness IC card with stepped portions at its side edges.
2. Description of the Related Art
In electronic devices such as cellular phones, telephones, PDAs and digital cameras, a variety of functions are added by inserting an IC card with a built-in memory or a control IC, such as a SIM (subscriber identity module) card and an MMC (multimedia card).
In a connector structure for removably accommodating such an IC card, a plurality of contact terminals made of a metal leaf spring are provided in a connector housing to contact a plurality of contact pads formed on the front or back surface of the inserted IC card to bring the IC card into electrical contact with the electronic device having that connector. The contact pads of the IC card include a power supply pad connected to a power supply line and a plurality of signal pads for transferring various signals. These contact pads are connected via the contact terminals of the card connector to a power supply circuit and various signal processing circuits in the electronic device.
FIG. 9 shows a general construction of the contact terminals and their associated components in the connector into which the IC card of this kind is to be loaded.
In FIG. 9, a base plate 101 of the connector housing 100 is formed with a plurality of support grooves 103 to support contact terminals 102. The contact terminals 102 are secured to the base plate 101 by fitting under pressure the side edges of fixed portions 102a thereof into press-fit grooves 105 formed in the side walls of the support grooves 103. Spring contact portions 102b of the contact terminals 102 are elastically deformed by the inserted card and brought into pressing contact with the contact pads of the card with a predetermined contact pressure. Terminal portions 102c of the contact terminals 102 are connected to a printed circuit board by solder.
In a connector which accommodates a card having contact pads on its underside, the contact terminals 102 are arranged below or above the card so that they can be elastically displaced and brought into contact with the contact pads. When the mounting area of the connector is to be reduced, the contact terminals 102 are arranged in the connector housing in such a way that the terminal portions 102c of the contact terminals 102 that are to be soldered will not protrude out of the connector housing but stay below the card.
It is therefore considered most effective in reducing the mounting area of the connector to form the support grooves 103 for securely holding the contact terminals 102 in the base plate 101 of the connector housing and provide the support grooves 103 with some means for securing the contact terminals 102, as shown in FIG. 9.
An IC card 20 as shown in FIG. 10 and FIG. 11 has been proposed in recent years. FIG. 10 shows the surface of the card where the contacts are arranged and FIG. 11 shows the opposite surface.
This card 20 is called an SD (super density or secure digital) card and has an upper body portion 21 with a thickness of t1. It has an almost triangular notched portion 22 on the right front end portion for preventing erroneous insertion of the card. On the back side of the upper body portion 21 is formed a lower body portion 23 with a thickness of t2 and a width slightly narrower than the upper body portion 21. The card 20 therefore has a stepped portion 27 formed at both side edges by the underside of the upper body portion 21 and the underside of the lower body portion 23.
On the front end side of the lower body portion 23 there are formed a plurality of recessed portions 24 separated from one another by a plurality of partition walls 29. Contact pads 25 are placed in these recessed portions 24. The depth of each recessed portion 24 is almost equal to the height of the lower body portion 23. Hence, the surface of each contact pad 25 is situated away from the front surface of the upper body portion 21 by the thickness t1 of the upper body portion 21. A write protect switch 26 is provided at the side surface of the card 20.
FIG. 12 shows the card 20 inserted into the connector of FIG. 9.
As shown in FIG. 12, in the connector structure of FIG. 9, the card 20 must be held so that the undersides of the partition walls 29 of the card 20 abut against the upper surface of the housing base plate 101.
Thus, in the connector structure of FIG. 9, the connector requires a height at least equal to the sum of the thickness h1 of the housing base plate 101 formed with the support grooves 103, the thickness t1+t2 of the card 20 (distance from the upper surface of the upper body portion 21 to the underside of the lower body portion 23) and the thickness h2 of the housing top plate. As a result, the height of the connector housing becomes large.
Under these circumstances, the present invention has been accomplished to provide a card connector which can reduce the height of a connector structure that receives a card having contact pads arranged in recessed portions separated from one another by partition walls.
In the present invention, a card connector for holding a card in a connector housing, wherein the card has an upper body portion, a lower body portion slightly narrower in width than the upper body portion and formed with a row of a plurality of recessed portions separated from one another by a plurality of partition walls, a plurality of contact pads placed in the recessed portions, and stepped portions formed at its both side edges by an underside of the upper body portion and an underside of the lower body portion, the card connector comprising: a plurality of contact terminals arranged in the connector housing and elastically deformed by the inserted card to contact the contact pads; and a plurality of contact supports each made up of a pair of raised portions with a support groove to support the associated contact terminal formed between the raised portions; wherein an overall width of each of said contact supports is smaller than an interval between said partition walls of the card, and said contact supports are formed projecting from the connector housing at a predetermined pitch corresponding to the interval between said partition walls so that said partition walls of said card fit between said contact supports when the card is inserted into the card connector.
According to the invention, since the connector of this invention supports the card in such a manner that the partition walls of the card fit between the plurality of contact supports each made up of a pair of raised portions, the thickness of the connector can be reduced by an amount virtually equal to the height of the raised portions fitted between the partition walls. The height of the connector can therefore be reduced.
As described above, because the connector of this invention supports the card in such a manner that the partition walls of the card fit between the plurality of contact supports each made up of a pair of raised portions, the thickness of the connector can be reduced by an amount virtually equal to the height of the raised portions fitted between the partition walls. The height of the connector can therefore be reduced.
The above and other objects, effects, features, and advantages of the present invention will become more apparent from the following description of embodiments thereof taken in conjunction with the accompanying drawings.